Hi Andulamb,
A comment on your master parenting techniques. Instead of always picking a male to drop on the female, try reversing the roles. Let your females instigate the breeding opportunity. If you watch you will notice that the villager who makes the first move gets the boost in skills. But I also agree that nursing moms should be able to participate in some activities. Maybe they could join in on the mushroom or egg collecting; or get an equal boost for breeding. After all, making babies is hard work for a mom, both before and after birth.